Authentication operations serve to check that a requestor requesting access to restricted resources is indeed that requestor. Authentication requestors can be applications, systems, embedded devices, devices, and are often people. Examples of authentication operations include username/password verification, one-time password verification, knowledge-based authentication, biometric-based authentication, and adaptive authentication.
Conventional authentication approaches involve employing one or more such authentication operations in response to a request to access restricted resources. For example, access to a gaming account on a smartphone may require simple username/password verification, but access to top-secret government or corporate information may require a combination of biometric and knowledge-based authentication.